This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Structure determination of the Ferm domain of Pyk2 in complex with the C-terminal domain of Nir2 We have obtained crystals of Ferm domain of Pyk2 in complex with the C-terminal domain of Nir2 that can elucidate how the C-terminal domain of Nir2 binds to the Ferm domain of Pyk2 and regulates Pyk2 activation and signaling. Intense crystal optimization of the complex as well as cryoprotectant search has been pursued yielding the datasets of resolution limit of 3.5 [unreadable] at X29 at Brookhaven. The limit of diffraction ranges of the crystals turned out to be caused by the cryoprotectants since the room temperature diffraction in the capillary gave higher resolution. However, the exposure of crystals to the beam at room temperature rapidly damaged crystals resulting that the data collection at room temperature is unlikely. Due to the nature of the complex crystals, we need newly developed technique, the high-pressure cooling. In collaboration with Dr. Sol M. Gruner and Dr. Chae Un Kim at Cornell, we are attempting to improve the resolution of our crystals using their newly developed high-pressure cryocooling approach. We are therefore requesting one (or two) day beam time at CHESS to test the effects of high-pressure cryocooling on the diffraction properties of these crystals, and if successful, collecting full native datasets.